Fan rotors



March 22, 1966 LAlNG ET AL 3,241,743

FAN ROTORS Filed Jan. 12, 1962 4 Sheets-Sheet 1' NIKoLAus me INQEBORG LAlNG INVENTORfi.

ATTORNEY BY i March 22, 1966 1. LAING ET AL FAN ROTORS 4 Sheets-Sheet 2 Filed Jan. 12, 1962 G W A L G R w E O m.

INVENTOR5.

ATTORNEY March 22, 1966 LAlNG ET AL 3,241,743

FAN ROTORS Filed Jan. 12, 1962 4 Sheets--Sheet 5 Flag N JKOLP" LAING mcmmzn; LAm-gr.

INVENTORs W MW ATTORNEY March 22, 1966 1, LA|NG ETAL FAN ROTORS 4 Sheets-Sheet 4.

Filed Jan. 12, 1962 N XKOLA US LAlNG INGEBORG LAfiN-S IN VENTOR$ BY W WiwmMQU ATTORNEY United States Patent 3,241,743 FAN RDTORS Ingeborg Laing, Rosenlhergstrasse 24a, Stuttgart, Germany, and Nikolaus Laing, Stuttgart, Germany; said Nikolaus Laing assignor to said Ingeborg Laing Filed Janu I2, 1962, Ser. No. 165,919 (llaims priority, application Germany, June 21, 1961,

3 9 7 Claims. ((11. 230-134) The invention relates to a drum-rotor fan, especially a cross-flow fan, the rotor of which is provided with angularly spaced blades, and to a method for manufac turing this rotor.

The invention makes it possible also to manufacture the drum rotor, which may be provided with hollow blades, of a rotary heat exchanger of a type described in concurrently filed copending application Ser. No. 165,765, now abandoned, in which a first heating medium, preferably air, is conveyed by the drum rotor in the manner of a cross-flow fan, and in which a second heating medium flows through the hollow blades parallel to the axis of the drum rotor.

The invention makes it possible also to construct a special rotary heat exchanger of this type in which the hollow paraxial blades are connected transversely by a plurality of ducts running in the circumferential direction. The invention further provides a suitable construction of a ribbed heat exchanger tube.

The drawing shows diagrammatically a number of constructional examples to illustrate the invention.

FIGURE 1 shows diagrammatically a first process for the manufacture of a drum rotor for a rotary heat exchanger consisting of a band.

FIGURE 2 is a portion of a perspective view of the drum rotor of a heat exchanger manufactured by the process illustrated in FIGURE 1.

FIGURE 3 is a .portion of a perspective view of the drum rotor of a fan manufactured by a modification of the process illustrated in FIGURE 1.

FIGURE 4 shows diagrammatically a second process for the manufacture of a drum rotor for a rotary heat exchanger from two bands.

FIGURE 5 is a portion of a perspective view of the drum rotor of a heat exchanger manufactured by the second process illustrated in FIGURE 4.

FIGURE 6 is a portion of a longitudinal section through the arrangement shown in FIGURE 5.

FIGURE 7 shows diagrammatically a third process for the manufacture of a drum rotor from two bands for a rotary heat exchanger.

FIGURE 8 shows diagrammatically a fourth process for the manufacture of a ribbed heat exchanger tube.

FIGURE 9 is a portion of a perspective view of a heat exchanger tube manufactured by the fourth process illustrated in FIGURE 7.

FIGURE 10 is a diagrammatic perspective view of an arrangement for carrying out the stage of the process which gives the sheet metal its trapezoidal cross section, using two conical rollers.

FIGURE 11 is a diagrammatic perspective view of an arrangement for carrying out the stage of the process which shapes the edges of the metal band, using two profiled rollers.

FIGURE 12 is a diagrammatic view of an arrangement for carrying out the stage of the process by which the free ends of the hollow projections are connected.

FIGURE 13 is a diagrammatic perspective view of an arrangement for carrying out the stage of the process by which the shaped edges of the sheet metal band are connected, using oscillating welding rollers.

In the process illustrated in FIGURE 1, a sheet metal 3,241,743 Patented Mar. 22, 1966 band 1 is taken from a supply roll 2 and passed between two conical rollers 3. The rollers act as drawing rollers which convert the rectangular cross section of the band into a trapezoidal cross section. The band 1 is thereby curved in the plane of the band so that it leaves the rollers 3 in the form of a helix. The band is then subjected to a process of intermediate annealing in an apparatus 4 in order to improve its structure, and it is then passed through a second pair of conical rollers and another intermediate annealing apparatus 6. The hand then passes through a deep-drawing apparatus 7 in which it is provided with hollow projections arranged at uniform intervals on one side of the band. These hollow projections have the cross-sections of blades in planes parallel to the plane of the band, and they are slightly conical. After passing through a further annealing apparatus 8, the band reaches a puncturing device 9 in which the ends or bottoms of the projections formed in the deep drawing apparatus 7 are punctured. The hollow projections formed in the deep drawing apparatus 7 are arranged at such intervals along the band that the projections of adjacent coils of the helical band are in alignment so that the free ends of the hollow projections enter into corresponding recesses at the attachments of the hollow projections of adjacent coils. The hand then passes through an apparatus 10 in which the free ends of the hollow projections are welded to adjacent coils of the band. The band is then finally reannealed in an apparatus 11 to remove tensions. Any desired lengths for drum rotors may be manufactured by the above-described process.

FIGURE 2 is a view in perspective of a portion of a drum rotor manufactured by the process illustrated in FIGURE 1. Three coils 20 are seen, which are provided with projections 21 extending to the left. The projections 21 are hollow and have the profile of fan blades. Owing to the fact that they are slightly conical, the free ends 22 of the projections 21 fit into the ends 23 of the projections, which are connected with the coils 20 of the band, with which projections they are permanently connected, for example by soldering. The intercommunicating projections 21 form hollow blade ducts running parallel to an axis 24 of the drum rotor. A liquid heating medium circulating through the heat exchanger formed by the drum rotor can flow through the said blade ducts.

FIGURE 3 is a view in perspective of a portion of the drum rotor of a fan manufactured by a modification of the process illustrated in FIGURE 1. The process used for manufacturing this drum rotor differs from that illustrated in FIGURE 1 in that there is no puncturing device 9 through which the ends of the hollow projections are removed. FIGURE 3 shows portions of three coils 30 of the band, which have hollow projections 31 pointing to the left. These projections are in the form of fan blades in profile and are closed by their free ends 32. The ends 32 are connected by point or spot welding with the sides of the coils 30 which are free from projections.

In the second process shown diagrammatically in FIG- URE 4 for manufacturing the drum rotor for a rotary heat exchanger, two bands 41, 41 supplied from two rolls 40, 40 are subjected to substantially similar processes. The bands 41 and 41 are twisted into spirals by rolling them twice with conical rollers 42, 42 and 42, 42" followed by annealing in apparatus 43, 43 and 43, 43". The bands then pass through profile rollers 44' and 44", by which the edges of the bands are shaped, as shown in FIGURES 5 and 11. After a further annealing treatment in an apparatus 45, 45' respectively, the bands 41, 41' are passed through a deep drawing apparatus 46, 46' in which they are provided with hollow blade-shaped projections (54 in FIGURE 5) and, if desired, also with ridges to increase their surface area, or with ribs by a process such as casting, spraying or the like. The blind ends of the projections are perforated in a puncturing apparatus 48, 48' after having passed through another annealing apparatus 47, 47. The two helical bands 41, 41' are then brought together so that their hollow projections made in the deep drawing apparatus, 46, 46, will be in contact. These hollow projections are then connected together in a spot welding apparatus 49 as shown in FIGURE 12. As shown in FIG- URE 13, the inner edges of successive turns of the two bands 41 and 41' are then welded together in a roller seam welding apparatus 50, and the outer edges are then welded together in a similar apparatus 51. The welding seams are then reannealed in an apparatus 52.

FIGURE 5 is a view in perspective of a portion of the drum rotor of a rotary heat exchanger manufactured by the process illustrated in FIGURE 4. Three coils 53 are shown, each composed of a band 41 and a band 41. The bands 41 and 41' are mirror images of one another and carry on one side hollow projections 54 with recessed ends which are connected by spot welding with the corresponding recessed ends of the hollow projections of the adjacent turn of the upper band. An inner portion 55 and outer portion 56 of each band 41 and 41 respectively are so shaped that they project on the side of the metal band remote from the hollow projections 54, so that a hollow helical duct 57 is formed between the bands 41 and 41'. The turns of this helical duct are connected together by ducts which run parallel to an axis 58 of the drum rotor and which are formed by the hollow projections 54.

FIGURE 6 is a longitudinal section of a portion of the arrangement shown in FIGURE 5. The same reference numerals are used as in FIGURE 5. The outer ends of the shaped portions 55 and 56 of the two bands 41 and 41' are connected together by rolled seams 60. The end surfaces of the hollow projections 54 which are in contact with one another are connected together by a welding seam 61.

The third process illustrated in FIGURE 7 for manufacturing a drum rotor from two bands for use in a rotary heat exchanger is substantially similar to that shown in FIGURE 4. Again it results in a drum rotor as shown diagrammatically in FIGURES 5 and 6. This third method differs from that shown in FIGURE 4 only in that two bands 71, 71 supplied from the rolls 70, 70 first pass together through conical rollers 72, an annealing apparatus 73, conical rollers 74 and another annealing apparatus 75. It is only then that the bands 70 and 71 are separated, each then passing through its own sectioning rollers 76 and 76' respectively for shaping the edges of the bands, apparatus 77, 77' for intermediate annealing of the bands, deep drawing apparatus 78, 78' for making hollow projections, apparatus 79, 79 for intermediate annealing of the bands, and puncturing apparatus 700, 700' for perforating the blind ends of the hollow projections. The hollow projections of the bands 70 and 71 are then connected together in a resistance welding apparatus 701 as shown in FIGURE 12. The inner and outer edges are then seam welded at stations 702, 703 as shown in FIGURE 13. The welding seams thus produced are then passed through an apparatus 704 in which they are again annealed.

FIGURE 9 is a perspective view of a portion of the ribbed heat-exchanger tube produced by the fourth process illustrated diagrammatically in FIGURE 8. A sheet metal band 81 is supplied from a roll 80 and passed successively through conical rollers 82, and intermediate annealing apparatus 83, conical rollers 84, a second intermediate annealing apparatus 85, sectioning rollers 86 to shape the edges of the band 81, and a third intermediate annealing apparatus 87. At the same time, a second metal band is taken from a roll 88 and passed through conical rollers 90, and intermediate annealing apparatus 91, conical rollers 92 and another intermediate annealing apparatus 93. The cross section of the band 89 is substantially that of an elongated rectangle whereas the band 81 is substantially of U-shaped cross-section. The two bands are united after passing through the apparatus and together they are passed through a resistance welding apparatus 94 in which the center of the U-shaped band 81 is bluntly welded to a side of the band 89, and the two bands are then passed through a seam welding apparatus 95 in which an inner edge of the band 89 is welded to the bent inner edge of the band 81 and the two bands are then passed through another seam welding apparatus 96 in which an outer edge of the band 81 is welded with a central region of the band 89.

FIGURE 10 shows diagrammatically in perspective an apparatus for shaping the trapezoidal cross section of a sheet metal band. A straight band 100 which has a long narrow rectangular cross section is passed through two conical rollers 101, 102. The cone angle has been greatly exaggerated in the drawing. These rollers stretch the band 100 unevenly transversely so that it leaves the latter in the form of a spiral band with a trapezoidal cross-section i.e. with converging longitudinal sides.

FIGURE 11 is a view in perspective showing diagrammatically an apparatus for shaping the edges and 111 of a sheet metal band 112, using two section or profiling rollers 113, 114. In the drawing, the edge 110 is already shaped while the edge 111 is being passed through the rollers 113 and 114.

FIGURE 12 shows diagrammatically two bands 124, with the ends 120, 121 of their hollow projections 122, 123 placed in contact with one another, and welding electrodes 126, 127 arranged in the hollow projections 122, 123.

FIGURE 13 is a view in perspective showing diagrammatically an apparatus used for connecting the shaped edges 131 and 132 of two adjacent coils of two bands 135 and 136 which are joined by their hollow projections 133, 134. This process is effected by passing two adjacent edges 131, 132 between two rollers 137 and 138. The welding end 139 of the roller 137 is conical and the shaft 140 of the roller 137 is slightly inclined to the plane of the bands 135, 136 so that the rollers 137 avoid contact with the previously welded edge 141. The axis 142 of the second roller 138 is substantially perpendicular to the plane of the bands 135, 136. As there is only a very limited amount of space available for the welding rollers and their mounting means, the rollers are suspended and they are oscillated by means not shown in the drawing. The oscillating movement is such that a part of the contact pressure exerted by the welding rollers on to the edges 131 and 132 is provided by a dynamic mass force. The forward velocities and the frequencies of oscillation are so adjusted to one another that a tight seam is produced.

We claim:

1. As a new article of manufacture, a helically wound strip of sheet metal with generally fiat turns transverse to the helix axis, and a plurality of angularly spaced axially extending tubular projections having throughgoing internal cavities integral with said strip, each projecting from one of said turns into engagement with an adjacent turn while being secured thereto in alignment with projections of said adjacent turn to form axially extending passages along the aligned internal cavities of said projections.

2. A process for making heat exchangers and the like, comprising the steps of helically winding at least one strip of sheet metal with generally fiat turns transverse to the helix axis and axially spaced apart to form fluid channels therebetween, forming said strip with a plurality of integral hollow projections extending axially from the turns thereof across said channels while being angularly spaced about said axis by deep drawing said projections from said strip with uniform spacing therealong, and securing the projections of each turn to an adjacent turn.

3. A process for making a drum-shaped member for fan rotors, heat exchangers and the like, comprising the steps of helically winding at least one strip of sheet metal with generally flat turns transverse to the helix axis, forming said strip with a plurality of integral tubular projections with respective throughgoing cavities extending axially from the turns thereof while being angularly spaced about said axis, and securing the projections of adjacent turns in mutual alignment with the cavities of the aligned projections providing throughgoing passages for a fluid each extending over a plurality of projections.

4. A process for making a drum-shaped member for fan rotors, heat exchangers and the like, comprising the steps of permanently deforming and winding at least one longitudinally extending strip of sheet metal into a multiturn helix with generally fiat turns transverse to the helix axis by passing said strip between a pair of conical rollers having coplanar axes generally inclined with respect to said strip and transverse to the direction of displacement thereof, and annealing said strip upon passage between said rollers; forming said strip along only one surface thereof with a plurality of perpendicular integral tubular projections extending axially from the turns thereof while being angularly spaced about said axis by deep drawing said projections from said strip with uniform spacing therealong, and removing the bottoms of said perforations; and securing the projections of each turn to a surface of an adjacent turn free from said projections in alignment with the projections thereof to provide a throughgoing passage for a fluid including a plurality of said projections.

5, A process as defined in claim 4 wherein the projections of each turn are secured to the adjacent turn by resistance welding.

6. A process as defined in claim 4 wherein the projections of each turn are secured to the adjacent turn by soldering.

7. A drum-type rotor for fans, rotary heat exchangers and the like comprising a plurality of spaced-apart turns of a helically wound strip of sheet metal, the turns extending generally transversely to the axis of the helix and having integral hollow projections extending axially to respective adjacent turns and secured thereto, said hollow projections having aerodynamic bladelike profiles and being inclined to respective radii of the helix through the projections.

References Cited by the Examiner UNITED STATES PATENTS 929,129 7/1909 Harder 230134 1,896,502 2/1933 Whitaker 182 X 2,042,537 6/1936 Liddell 29-163.5 X 2,643,863 6/1953 Buschow 29163.5 X 2,654,124 10/1953 Layte 29163.5 X 2,684,521 7/1954 Morrison 29156.8 2,833,464 5/1958 Sharp 230-1345 2,980,990 4/1961 Sprouse 29156.8

FOREIGN PATENTS 609,805 11/1960 Canada.

548,474 4/1932 Germany.

WHITMORE A. WILTZ, Primary Examiner.

JOSEPH H. BRANSON, Examiner. 

1. AS A NEW ARTICLE OF MANUFACTURE, A HELICALLY WOUND STRIP OF SHEET METAL WITH GENERALLY FLAT TURNS TRANSVERSE TO THE HELIX AXIS, AND A PLURALITY OF ANGULARLY SPACED AXIALLY EXTENDING TUBULAR PROJECTIONS HAVING THROUGHGOING INTERNAL CAVITIES INTEGRAL WITH SAID STRIP, EACH PROJECTING FROM ONE OF SAID TURNS INTO ENGAGEMENT WITH AN ADJACENT TURN WHILE BEING SECURED THERETO IN ALIGNMENT WITH PROJECTIONS OF SAID ADJACENT TURN TO FORM AXIALLY EXTENDING PASSAGES ALONG THE ALIGNED INTERNAL CAVITIES OF SAID PROJECTIONS. 